A common shock absorber arrangement includes a piston slideably disposed in a cylinder, with hydraulic fluid displaced through a series of orifices by movement of the piston in the cylinder to absorb shock loads and generate viscous damping. Such shock absorbers are employed in applications such as machine tool stops to absorb the momentum of moving machine tool parts as they are brought to a stop.
One such shock absorber arrangement is disclosed in U.S. Pat. No. 4,059,175. The shock absorber disclosed therein includes a piston member having a relatively large diameter piston head and a relatively small diameter piston rod which is slideably mounted within a bearing sleeve retainer configured with two spaced large diameter sections thereof and an intermediate and end sections of relatively small diameter. Both the piston and bearing sleeve retainer are constructed of a single unitary piece.
These parts, being required to withstand relatively high pressure forces, are machined from solid steel bar stock. The relatively large volume of material which must be machined away to form the finished parts represents a considerable wastage of material, contributing significantly to the cost of these components. It would therefore be advantageous if such components could be manufactured so as to reduce the overall cost of the shock absorber, by eliminating such material wastage.
Accordingly, it is an object of the present invention to provide a shock absorber of the type including a piston and rod assembly slideably mounted within a cylinder chamber, with the piston of two piece construction with separate head and rod portions thereof joined together in order to reduce the cost of manufacturing the shock absorber assembly.
A still further object of the present invention is to provide a shock absorber of the type including a bearing sleeve retainer, which bearing sleeve retainer has various diameter sections, which is of three piece construction rather than one piece construction, in order to reduce substantially the manufacturing cost of the component.
Yet another object of the present invention is to provide a manufacturing technique for press fitting separate elements into a single unitary high strength component suitable for use in such shock absorber application.